Isomers of diels-alder adducts of hexahalocyclopentadiene with quinones



Patented Feb. 5, 1952 UNITED STATES PATENT OFFICE rsoivm'ns 0F DIELS-ALDER. ADDUCTS OF HEXAHALOCYCLOPENTADIENE WITH QUIN ONES Edward Segel, Rex E. Lidov and Julius Hyman,

' Denver, Colpzrsaid Segelandsaid Lidov assignor's to VelslcoI Corporation, Chicago, 111., a

corporation of Illinois No Drawing. Application August '7, 1948, Serial No. 43,153

12 Claims. (01. 260-625) This invention relates to new compositions of matter and to methods of preparation of said compositions.

The compounds which are the subject of this invention are useful as fungicides, bactericides,

insecticides, and are further useful as intermediates to produce other valuable materials which may have a diversity of uses.

More specifically, thi invention is concerned with the rearrangement of or isomerization to hydroquinones of the Dials-Alder adducts of hexahalocyclopentadienes and quinones. Such Diels-Alder adducts have been disclosed and claimed in the copending application by Lidov, Hyman and Segel, Serial No. 794,204, filed D'ecember 27, 1947. I

The present invention is concerned with those products of the aforementioned reactants wherein the structure to be rearranged has contained therein a 1,4-diketonecyclohexene-2 ring structure, and further contains a hydrogen atom in each of the two angular positions formed when the two aforementioned reactants combine.

Thus, specific compounds exemplary of those which can be rearranged to form hy'droqu'in'ones according to the present process are represented by the following formulas:

I Where X is either chlorine, bromineor mixtures thereof. Thus, compound Ais the Diels-Alder reaction product of a hexahalocyclopentadiene as previously described and benzoquinone. Compound B is the reaction product of a hexahalocyclopentadiene as previously described and naphthoquinone.

DielseAlder adducts of a hexahalocyclopentaclone and a quinone of" the-group having the formula:

and,

wherein R1, R2, R3 and R4 are of the group consisting. of hydrogen, halogen, and organic radicals are applicable to the present process.

The rearrangement reaction of quinone adducts typified and described above can be generically represented as follows:

wherein Xis' halogen as previously described and R1, R2, R3 and R4 are chosen from the grouphydro'gen, halogen and organic radicals.

Thus, in the first reaction above, R1 may, for example, be hydrogen, chlorine, bromine or a phenyl, methyl, ethyl, or other group, while R2 is'hydrogen chlorine, bromine; or a phenyl, methyl, ethyl, or other group.

Similarly, in the latter reaction above represented', R1, R22, R; and R4, may all, or any of them, be hydrogen, chlorine, bromine, or methyl; ethyl,

and phenyl groups, or the like.

, Broadly; the rearrangement reaction herein described. ma be effected by mildly heating the aforementioned Diels-Alder adducts in a basic medium for a relatively short period of time.

More specifically; and to further exemplify without restricting those compounds which can be utilized in the present process, the following structures are presented:

o 01 HI Cl-C431 o1 The temperature of reaction may vary between about normal room temperature to about 2QQf- C.' and preferably between about 60 to about 120C. At below about normal room temperature, the reaction proceeds too slowly to be accomplished advantageously. Diluents for the reaction may be such solvents as methanol, ethanol, benzene,

hexane, heptane and the like. For ease of operation, the reaction is generally accomplished at the reflux temperature of the solvent utilized, and

since the particular solvent utilized is generally not critical, many suitable solvents for accomplishing the present reaction will be suggested to one skilled in the art.

The base utilizedmay be organic, such as' morpholine, pyridine, triethanol amine, aniline,

butyl amine, and the like, or may be inorganic,

such as ammonia, sodium hydroxide or potassium hydroxide. The type of base best utilized'in each specific instance will depend to some extent on the type of solvent or diluent utilized. Thus, sodium and potassium hydroxide are well suited if the reaction takes place in methanol or ethanol. On the other hand, pyridine or triethanol amine are well suited if the reaction takes place in benzene, hexane, methanol and the like.

The amount of base utilized may vary over a fairly wide range, and an extremely small amount can efiect rapid rearrangement. Thus, methanol, having a pH of about 7.4 is sufiiciently basic to effect rearrangement at a reasonable rate. Increasing the concentration of base increases the rate of reaction.

To more Tully illustrate the present'process, the following examples are presented for purposestof illustration and are not intended to. limi the intio n a w q 1 EXA PLE 1- Isomerization of the adduct of hezrachlorocyclo pentadz'ene and benzoquihone I 1 The Dials-Alder adduct of hexachloro'cyclopentadiene and benzoquinone (80 g'.) was dis.- solved in boiling methanol (pH-=73) and refluxed for six hours. The mixture was then cooled'to room temperature and chilled in an ice bath; this resulted in the deposition of white solid which was identified as the hydroquinone obtained by rearrangement of the starting adduct. 7

EXAMPLE 2 Isomerizatz'on of the adduct of hexach lorolcjjclo} pentadiene and phenylbenzoqm'none about 10 minutes) and then a few' drops sulfuric acid were added. The solution was evaporated to about one-half volume and then water was added to precipitate a white solid which was identified as the hydroquinone obtained by rearrangement of the starting adduct.

EXAMPLE 3 dIsomerizatz'on of the adduct of hewachlorocyclo- 5. pentadiene and toluquinone The Diels Alder adduct of hexachlorocyclopentadiene and toluquinone (3.7 g.) was dissolved "in a mixture of methanol and ethanol. Pyridine (1.5 ml.) was added and the mixture was refluxed for two hours. The mixture was acidified, reduced in volume, diluted ,withqwater and chilled. This resulted in the precipitation of a white solid identified as the hydroquinone obtained by rearrangement of the starting adduct.

EXAMPLE 4 v.;

'Isomerz'zatzon of the adduct 0 hexachlorocyclo pentadiene and benzoquinone The Diels-Alder adduct of hexachlorocyclopentadiene and benzoquinone (2.0 g.) wasdissolved in benzene to which was added pyridine (1 ml.). The mixture was refluxed for onehour. The solution became colorless, and upon. removing the benzene solvent by distillation in vacuo, a white solid was obtained which was recrystallized from a hexane-benzene mixture. The .thus obtained crystalline material was identified as the hydroquinone obtained by rearrangement of the starting adduct.

EXAMPLE 5 Isomerz'zatzon of the adduct of heccabromocyclopentadiene and benzoquz'no e Isomerization of the adduct 0 hewachlorocyclopentadiene and benzoqui one The Diels-Alder adduct of hexachlorocyclopentadiene and benzoquinone (3 g.) was placed in methanol (20 ml.), and to this mixture was added five drops or morpholine. 'Aiter refluxing the mixture for 15 minutes, it was chilled, and the deposited white crystals were identified as the hydroquinone obtained by rearrangement Otthe starting adduct. 7 Y

7 EXAMPLE '1 1- Example 6 was repeated except that triethanol amine was used in place of morpholine... The

hydroquinone obtained by rearrangement'of the starting adduct was again obtained.

EXAMPLE 8 Isomerization of theAdductof Hexachlorocyclopentadiene and Benzoquinone The Diels-Alder adductof hexachlorocyclopentadiene and benzoqulnone (3 g.) was dissolved The examples'h'ereinbefore listed are obviously not completely comprehensive as to possible variations in technique and procedure, and various modifications thereof will be suggested to those skilled in'theart without departing from the scope or spirit of the invention.

As a non-fully equivalent alternative "liqjthe process, as hereinbefore related, rearrangement -cr .;isomerization of the previously defined adducts to form hydroquinones may be effected by heating said adducts (between about 100-200 C.) in relatively concentrated sulfuric acid (containing in excess of about 50% acid) for short periods of time. Thus, heating the adduct of hexachlorocyclopentadiene and benzoquinone in 98%, 95%, 90% and 80% sulfuric acid for periods of time from about five to about 30 minutes at temperatures of from about 110 C. to about 180 C. resulted in the formation of the isomerized product herein concerned.

The hydroquinones obtained according to the :2

present process are valuable compounds in that they exhibit excellent bactericidal, fungicidal, and insecticidal properties. In addition thereto, the products of the present process are useful intermediates in the preparation of other new and and wherein X is a halogen of the group consisting of chlorine and bromine and R1, R2, R3 and R4 are of the group consisting of hydrogen, halogen and, alkyl and aryl radicals.

2. A new composition of matter comprising a Further, said isomerized i 6 of a hexahalocyolopentadiene and a quinone of the group having the formula I and wherein R1, R2, R3 and R4 are of the group consisting of hydrogen, halogen, alkyl and aryl radicals.

3. A composition according to claim 2, wherein the hexahalocyclopentadiene is hexachlorocyclopentadiene.

l. A composition according to claim 2, wherein the quinone is benzoquinone.

5. As a new composition of matter, the hydroquinone isomer of the Diels-Alder adduct of hexachlorocyclopentadiene and benzoquinone.

5. As a new composition of matter, the hydroquinone isomer of the Diels-Alder adduct of hexachlorocyclopentadiene and naphthoquinone.

7. As a new composition of matter, the hydroquinone isomer of the Dials-Alder adduct of hexachlorocyclopentadiene and phenylbenzoquinone.

8. As a new composition of matter, the hydroquinone' isomer of the Diels-Alder adduct of hexachlorocyclopentadiene and toluquinone.

9. As a new composition of matter, the hydroquinone isomer of the Diels-Alder adduct of hexabromocyclopentadiene and benzoquinone.

10. The method of formingthe hydroquinone isomer of the Diels-Alder adduct of a hexahalocyclopentadiene and a quinone of the group having the formula:

and g H Ra wherein R1, R2, R3 and R4 are of the group consisting of hydrogen, halogen, alkyl and aryl radicals, which comprises reacting said adduct in a basic medium.

11. The method of forming thehydroquinone isomer of the Diels-Alder adduct of a hexahalocyclopentadiene, wherein the halogen substituhydroquinone isomer of the Diels-Alder adduct '75 ents are of the group consisting of chlorine and bromine, and a quinone of the group having the formula:

wherein R1, R2, R3 and R4 are of the group consisting of hydrogen, halogen alkyl and aryl radicals, which comprises reacting said adduct' contained in a diluent in the presence of a basic catalyst at a temperature of about normal room temperature to about 200 C.

12. The'process of claim 11, wherein the temperature is about to about C. and the diluent is a solvent for the reactants.

EDWARD SEGEL. REX E. LIDOV. JULIUS HYMAN.

REFERENCES CITED The following references are of record in the file of this patent:

Norton, Chem. Reviews, vol. 31, page 340 (1942) (1 page only). Entire article pages 319-523.

Prill, J. Am. Chem. 500., vol. 69, pages 62-63 (1947) (2 pages). 

1. A NEW COMPOSITION OF MATTER COMPRISING THE MATERIAL CHOSEN FROM THE GROUP HAVING THE FORMULA: 